The Dictator chooses either fair or competitive allocation while selecting the competitive allocation is irrelevant to increasing the Dictator’s payoffs. The Recipient decides whether to accept the Dictator’s decision or receive sure but low rewards. We found that Recipients with high-level paranoid thinking expected their opponent to select competitive allocation more than those with low levels, even when selecting it was costly for Dictators. Paranoid thinking was not associated with selecting sure rewards or competitive allocations. The results suggest that paranoia reflects the belief that others have a competitive intention but is not related to avoidance behavior against perceived threats and unilateral attacks.Paranoid thinking, that others are hostile, can be seen even in the general population. Paranoia is considered the expectation that others are competitors who aim to maximize the differences in payoffs rather than maximize their own payoffs. This study examined whether paranoia reflects the irrational belief that others have a competitive intention and is associated with avoiding perceived competition. We recruited 884 US residents  Paranoia is an unfounded concern that others have intentions to harm . Paranoie.g., desire to reduce Recipients’ payoff) or self-interest . Previous studies have demonstrated that recipients with higher paranoid thinking tend to attribute unfair Dictator’s decisions to harmful intent, although the attribution of self-interest does not differ between paranoia levels   plays a Recent studies have provided evidence that paranoia is the tendency to infer the intentions of others as harmful rather than self-interested . In othee.g., $0.5) and decide whether to attack their partner or not. If neither of them chooses to attack during the allotted time, both receive the initial money . If one of them attacks the partner first, they must pay a small cost . In contrast, the attacked partner loses a larger amount of money . Attacks in the PSG are against maximizing their own payoffs; therefore, there is no reason for people with an individualistic orientation to engage in an attack. People who believe that others are rational would not choose to attack them. However, preemptive attacks can occur driven by the fear that others may have a competitive orientation. Indeed, the PSG experiment observed people who engaged in preemptive attacks because they were driven by fear .Previous studies have used DG to examine the connection between paranoid thinking and attribution of the Dictator’s selfish behavior . However by fear . A previ by fear  showed tThe purpose of the present study is to examine in detail whether paranoia reflects the belief that others are competitors and is associated with behavior that avoids perceived competitive intention. Although the motivations behind attacking behavior in PSG have been demonstrated to be mainly driven by defensive aggression , logicale.g., both the Dictator and the Recipient receive $0.5), and the other is a competitive one. According to the options used in the method for classifying SVOs . In the costly condition, if the Dictator chooses the competitive option, their earnings become less than those when choosing the fair option . In both conditions, for Dictators, choosing the competitive option is irrelevant to maximizing their payoff. After the Dictator has made their decision, the Recipient decides whether to receive the money according to the Dictator’s decision or choose an avoidance option. If the Recipient chooses the avoidance option, they can receive a fixed amount of money . This amount is higher than when the Dictator has chosen the competitive option but lower than when they have chosen the fair option . Moreover, our DG reflects a situation in which the reasons for the Dictator’s unfair behavior are more likely to be attributed to competitive orientation rather than individualism. By observing the behavior of the Recipients, we expect to rigorously examine the link between the supposition of competitiveness and avoidance of perceived harm in paranoia.In the non-costly condition, choosing the avoidance option would reflect the belief that others were competitors rather than prosocials who cared about the interests of others. Furthermore, the costly condition is a situation in which choosing a competitive distribution is inconsistent with maximizing self-interest. Therefore, in the costly condition, selecting the avoidance option would imply a strong belief that others’ orientations were competitive rather than individualistic. Thus, participants who believe that general people behave as competitors may choose the avoidance option in this game, and such a belief may be observed among those with higher paranoid thinking. A questionnaire survey indicated an association between persecution delusions and self-reported experiences of avoiding threats . Howeverhttps://osf.io/9s5tf/?view_only=9c62cf2b64324b47a48869a94fcbd8ea):We examined the following pre-registered predictions concerning the Recipients’ behavior . For recruitment, we used the MTurk toolkit and randomly recruited participants from the “CloudResearch-Approved Participants” pool provided by CloudResearch (www.cloudresearch.com)  . This porch.com) : the numwww.qualtrics.com).We recruited participants for a pre-survey to measure their paranoia scores. Seven days after completing the data collection for paranoia scores, we invited the same participants to participate in the DG. After sending the invitations, we stopped data collection when the number of participants in the DG dropped below two per day, according to the pre-registered plan to collect the data. In the DG, we set the conditions as between-subject factors, and participants were randomly assigned to either the costly or non-costly condition. Questionnaire forms for the pre-survey and the DG were developed using Qualtrics  years, ranging from 18 to 78 years. We gathered 478 Dictators; 243 were assigned to costly conditions and 235 to non-costly conditions. We gathered 406 Recipients; 206 were assigned to costly conditions and 200 to non-costly conditions.Finally, we collected a total of 884 participants . The mean age of the participants was 39.72  . The R-GAfter completing the R-GPTS, participants were asked about their gender  and age. Each participant was paid 0.60 United States dollars (USD) as a reward for participating in the pre-survey.Participants were paid 0.60 USD as remuneration to participate in the experiment. Additionally, they could receive earnings in the DG as bonuses. The instructions for the DG are provided in the First, the participants were provided with instructions for the DG. In the instruction, the Dictator and the Recipient were referred to as “Player 1” and “Player 2,” respectively. Participants were told that they were randomly paired with another participant and assigned to either the Dictator or the Recipient. Money was allocated only once between the two.The Dictator decided the allocation by selecting one of the two options that an experimenter prepared. Referring to “decomposed games” used for measuring SVO , we presi.e., the avoidance option: referred to as option Y) without being informed of the actual decision by their partner. We instructed the Recipients that the Dictators had not been informed that the Recipients would make the decision. After collecting all data on the Recipients, each Recipient was paid a bonus based on the outcome of the game. Those who chose to receive the money allocated by the Dictator were randomly paired with one of the Dictators and received the money according to their partner’s decision. Those who chose the avoidance option received 0.30 USD.The Recipients were informed of the two allocation options presented to the Dictator according to their assigned condition and that they took their decisions by selecting either the fair or competitive options. Recipients decided to choose either “to receive the money according to the Dictator’s decision” (referred to as option X) or “to receive 0.30 USD for sure”  using a slider measure from 0% to 100% in increments of 1% . Subsequently, according to methods implemented in previous studies , they alThis research was approved by the Ethics Committee for Human Psychological Research at Teikyo University (No. 627) and was performed per relevant guidelines. Before participating in this study, all participants read a consent form, and informed consent was obtained. They were informed that participation in the study was voluntary and agreed to participate by anonymously checking a box on the consent form page. They could withdraw from participating in the study by closing the web page, even after agreeing to participate.R version 4.2.2  was usedi.e., mean). Thus, the slope of the paranoia score in each model indicates the average effect on the response variable across the two conditions. We also estimated the condition-specific effects of the paranoia score on the response variables from the inferred parameters in the models.We used regression models when testing pre-registered predictions and conducting unplanned analyses. In the regression models, we added paranoia score, condition , participants’ gender , and age as predictors. We also added an interaction term between the paranoia score and condition as a predictor. The addition of the interaction term results in a slight deviation from the pre-registered analysis plans; however, it is intended to conduct more robust analyses to test whether the paranoia score has different effects depending on the conditions. Binary predictors were centered by subtracting from their mean, and continuous predictors were standardized. This coding allowed us to interpret the coefficient of each predictor as the average effect on the outcome when all other predictors were zero  and performed ordinal regression models rather than linear models because of the skewness of the distributions. We also reported the results using linear regression models instead of ordinal regression models in the According to previous studies , when wei.e., intervals) of the parameters in the models. For each model, we reported the posterior mean, standard deviation, and 95% credible intervals (CI) of the parameters. If the 95% CI does not overlap zero, it is similar to the significant effect at the 5% level in the statistical null hypothesis test with the frequentist statistics. A “brms” package was used to conduct the Bayesian regression analyses (We estimated the coefficients of the regression models using Bayesian estimation with Markov Chain Monte Carlo (MCMC) simulations. The Bayesian estimation inferred the posterior distributions .The average paranoia score of the Dictators was 6.01 , whereas that of the Recipients was 6.47 . p = 0.25).We found that 1.65% (4/243) and 3.40% (8/235) of Dictators chose the competitive options in the costly and the non-costly conditions, respectively. We found no significant difference in the frequency of competitors between the two conditions (Fisher’s exact test: p = 0.19).Moreover, we found that 25.73% (53/206) and 32.0% (64/200) of Recipients selected the avoidance option in the costly and non-costly conditions, respectively. There was no significant difference in the frequency of Recipients who chose the avoidance option between the two conditions  as predictors.We performed an exploratory analysis to find the factors affecting the probability of the Recipient choosing the avoidance option using all the obtained variables. We performed a logistic regression using the Recipients’ decisions as a response variable. We used the paranoia score, condition, the interaction term between the paranoia score and the condition, gender, age, and post-experimental questionnaire items  did not affect the Recipients’ decisions.We examined whether paranoid thinking was associated with the belief that others were competitors who aimed to maximize the difference in payoffs. In our DG, Dictators choose either fair or competitive allocation, while selecting competitive allocation does not increase their payoffs. The proportion of Dictators who chose competitive allocation was low. Nevertheless, most Recipients estimated a large number of competitors, even in the costly condition in which Dictators must incur costs if they choose the competitive allocation. Moreover, participants with high-level paranoid ideations were more likely to expect others to choose a competitive distribution and assume that others had harmful intentions than those with low-level ideations. The results suggest that overestimation of others’ competitive orientation could be observed as a common propensity among the general population. In addition, the current study indicated a strong association between paranoid thinking and the supposition of others’ harmful or competitive intentions in uncertain situations.However, we could not find an effect of paranoid thinking on enhancing behavior to avoid competitive allocations. The exploratory analysis revealed that the expectation of the Dictator’s competitiveness and the supposition of the Dictator’s harmful intention independently influenced the increase in avoidance behavior. A recent study reported no association between paranoid thinking and betrayal aversion : that isHowever, previous findings have indicated a relationship between paranoia and reactions to perceived threats. Paranoid thinking is associated with defection or distrust in economic games . Paranoii.e., payoff-maximizing) has been highlighted  to earn as much money as possible. The motivation to avoid perceived threats may counteract the desire to earn more payoffs. Therefore, this study may have found no association between paranoia and avoidance behavior. Other psychological variables reflecting a self-interested orientation, such as the participant’s own SVO, should be considered control variables.The lack of an association between avoidance and paranoid thinking in this study may also be attributed to other confounded variables. For example, the relationship between paranoia and the pursuit of self-interest in economic games  by observing the Dictator’s behavior. A previous study showed that people rarely engage in a preemptive strike when they can unilaterally reduce others’ payoffs . This study also strengthens the argument that pre-existing paranoid thinking represents a default lower threshold for detecting social threats, rather than strong reactivity or insensitivity to social contexts.We found no interaction between the paranoia scores and the conditions of the Dictator’s costs in selecting a competitive allocation. On a similar note, previous studies using economic games have confirmed the lack of interaction between pre-measured paranoia and experimental manipulations; participants with a higher level of paranoia are more likely to attribute others’ intentions as harmful than those with a lower level, irrespective of experimental conditions . PreviouAvoiding perceived threats leads to a repetitive cycle of persistent paranoid beliefs by preventing the processing of evidence that their belief is without foundation . ExploriThis study has some limitations. First, other potential mental health factors associated with paranoia should be controlled. Several mental health problems, such as depression, worry, and anxiety, are associated with paranoid thinking . Furthervia experiences. In addition, As previously mentioned, the need to measure SVOs of self was one of the limitations of the current study. A recent study showed the possibility that paranoia is associated with one’s own SVOs and predictions of others’ SVOs . Barnby,Paranoia has been observed to have a continuous propensity in a general non-clinical sample. The findings of this study also suggest that the general belief that others have a competitive orientation can be observed. Recently, the evolutionary foundation of paranoia as a normal psychological function has been discussed . AlthougIn this study, we examined whether paranoid thinking was associated with the supposition that others have competitive intentions using a modified DG. Although the Dictators who chose the competitive allocation option were rarely observed, some Recipients overestimated the other’s competitive intentions and avoided the Dictator’s allocations. Recipients with high-level paranoid thinking were more likely to anticipate that others would choose a competitive allocation and have harmful intentions, even if selecting the competitive option was costly for the Dictators. However, paranoid thinking did not strongly affect behavior to avoid competitive allocation. These results suggest that paranoid thinking acts as a function of detecting others’ competitive intentions, although the avoidance of perceived threats is not a general strategy in paranoia.10.7717/peerj.15003/supp-1Supplemental Information 1Click here for additional data file.


Potamopyrgus antipodarum, reproduces parthenogenetically in its invaded range, and a few distinct clonal genotypes have been identified in North America. Much of the spread of the snail in North America has been the result of unintentional overland transport by recreational water users. Thus, desiccation tolerance may play an important role in the invasion success of this species. The primary goal of these experiments is to determine if variation in desiccation tolerance exists between populations of this species. Here we compared multiple multi-locus genotypes (MLGs) and populations within those genotypes with regard to their desiccation tolerance. We conducted three experiments. The first compared the survival rate over time of snails from three populations and two MLGs with regard to their ability to survive being completely removed from water. The second experiment examined different size classes of snails from the same population, and the third experiment compared four different populations and two MLGs genotypes with respect to their survival rate over time when removed from water but being kept in moist conditions. We found larger snails tolerate desiccation longer than smaller snails with snails between 4 and 4.6 mm surviving at a rate of more than 50% after 12 h while smaller snails survived at a less than 5% rate after 12 h. We also found significant variation both between and within MLGs in their survival rate when completely removed from water and dried with the MLG from the western US having a more than 50% greater survival probability than the eastern MLGs at both 18 and 24 h out of water. When removed from water and kept moist all MLGs had a near 100% survival rate at 60 days at 7 °C, and most survived at a greater than 90% rate at 60 days at 17 °C, while no MLG’s survived past 30 days at 27 °C. The results demonstrate that variation for desiccation tolerance exists between populations of this invader which could influence the invasiveness of different populations.Traits in species that influence invasion success may vary in populations across its invaded range. The aquatic New Zealand mud snail,  Variation in traits may exist within and between populations of an invasive species . This vaPotamopyrgus antipodarum is an incredibly successful invader ,  invader  endemic  invader , Europe  invader , Asia , US1-WY , and US2-O29  were used in experiment 1, US1-PA was used in experiment 2, and US1-PA, US1-MD , US1-NJ , and US2-Syr  were used in experiment 3. All populations are invasive in North America, and a map of the locations of each population can be seen in ® and containing 3 ppt (parts per thousand) seawater, since these snails have been found to grow faster in dilute seawater than in freshwater  or between time of exposure . To expose the snails to air, the snails were removed from water and placed on a paper towel. They were blot-dried with another paper towel and then placed into an empty 50 ml plastic cup. The cups were placed on plastic trays, that could each hold up to 20 cups, with rows of each population on each tray. Separate trays were used for each treatment, and the trays were placed on a lab bench in the center of the lab. Placing all of the snails used for each treatment on the same trays did create a confounding variable. However, we did this to minimize errors that could be made in the execution of the experiment, and the trays were arranged in a way so that all of the cups were within 1 m of each other, and no differences in temperature or humidity were found between tray positions. The snails in the 0 h treatment were then immediately returned to water. The snails from the other treatments were returned to water at the appropriate time. It was determined that the snail was alive after being returned to water if the snail was observed to move. The snails retreated into their shells when out of the water. If alive, once reintroduced to water, the snails will eventually emerge from their shells and begin to crawl around. Mortality was assessed after 1 week.This experiment was conducted in July of 2017 using three invasive populations, two populations of the US1 MLG (US1-WY and US1-PA) and one US2 population (US2-O29) . The snails were taken from multiple containers of each population. We exposed snails from each population to air in the lab at a relative humidity of 19–24% with a constant temperature of 18 °C for one of six time periods: 0, 9, 18, 24, 36, or 48 h. A total of 30 snails in groups of 10 between 4 and 5 mm in length of the US1-WY and US1-PA snails were exposed in each time period, and a total of 27 of the US2-O29 (in groups of nine) were exposed in each time period (the difference was due to having fewer numbers of suitable sized snails from the US2-O29 population). The snails were selected to not differ in length between population  or temperature treatment . To expose the snails to moist conditions, we removed them from water and then put 10 snails at a time on a Scott® brand Multifold dry paper towel. The towel was then folded into approximately a 5 cm × 5 cm square so that the snails were in the center, and there were at least three layers of towel around the group of snails. A total of 6 ml of dechlorinated tap water treated with Amquel® was added to each towel to make it moist. This amount was chosen because 6 ml resulted in a saturated towel without excess water. Then for each temperature treatment all of the towels were placed together in a sealed 15 cm × 15 cm × 5 cm plastic box. The box was then placed in the appropriate temperature. The boxes were placed in a refrigerator for 7 °C, in a Styrofoam cooler covered with a lid for 17 °C, or in a covered warm water bath for 27 °C. A total of 30 snails (three replicates of 10) from each population were exposed to each temperature at each time interval, resulting in a total of 210 snails of each population being exposed to each temperature, thirty at each time period. For the 7 °C treatment, snails were assessed for survival at 0, 25, 40, 45, 50, 56, and 60 days. For the 17 °C treatment survival was assessed at 0, 10, 21, 30, 40, 50, and 60 days, and for the 27 °C treatment survival was assessed at 0, 10, 16, 22, 27, 30, and 36 days after wrapping the snails. These intervals were chosen based on preliminary experiments. Snails exposed for 0 days were immediately removed from the paper towel and re-exposed to water. Mortality was assessed in the same manner as in both earlier experiments.This experiment was conducted in the summer of 2019 using four different invasive populations, three populations of the US1 MLG  and one US2 population (US2-Syr). These populations were used because we had more of these snails reared in the lab than other populations, and only these could give us the sample sizes that we desired. The snails used ranged in size from 4 to 5 mm in length, and the snails did not differ in length between population  , suggesting that survival rate decreased with increasing temperature. Comparing populations within temperatures found significant differences between several populations . Thus, if snails are attached to items that are removed from water and stored in a cold area , it is quite possible that they may be able to survive for several months.We found that when snails were removed from water but kept moist, mortality increased over time at a greater rate as the temperature was increased from 7 °C to 27 °C. This is perhaps not surprising given that the metabolic rates of the animals increase with increasing temperature. The fact that there was almost no mortality at 7 °C for any population is consistent with the fact that these snails typically respond to cold temperatures by retreating into their shells and may overwinter this way . , thus US1-PA had the smallest sample size . While it makes sense that fungal growth would have a greater effect on the warmer treatments, since the temperatures were not properly replicated, we cannot be sure if the effect of the fungus was affected by temperature.P. antipodarum to desiccation in a moist environment created in a closed petri dish with a filter paper saturated with water. He found 100% mortality by 52 days with 90% mortality by about 30 days. Survival rates were higher in the present experiment. This could be due to the differences in how the experiments were conducted. P. antipodarum from water in leaf litter, artificial sediment, and clay. They found that the snails survived less than 3 days in the leaf litter, but there was greater than 20% survival after 4 days in both sediment and clay demonstrating that the material that the snails are transported in can influence the survival rate.P. antipodarum resist desiccation longer than smaller individuals. In addition, the results of experiment 2 are consistent with The results suggest that to control the spread of the snail, individuals should understand that the snails can live out of water for at least several hours, and if kept moist and cool, they could live for months. While some populations exhibit greater desiccation tolerance than others, all populations can survive for a time that allows for effective dispersal whether by animal  or humans if equipment, gear, and clothing are not sufficiently decontaminated. Water users should avoid wearing or using the same gear in multiple locations without efforts to decontaminate them when they are in an area known to be infested by NZMS.These experiments show evidence of variation in desiccation tolerance between populations of an aquatic invader suggesting that this trait is malleable in invasive NZMS populations. The fact that there are differences between populations of the same multi-locus genotype suggests that characterizing the traits of an invader should be done by examining populations from multiple locations, and populations from different locations should not be assumed to have the same traits including tolerances to biotic and abiotic stressors.10.7717/peerj.15732/supp-1Supplemental Information 1Click here for additional data file.


Dear Editor,We are writing to comment on Dağdelen et al.'s study on the measurement of the optic nerve sheath diameter (ONSD) in patients with idiopathic intracranial hypertension.Ocular ultrasonography is considered to be the least invasive diagnostic method to detect intracranial hypertension, even in an emergency setting.In their paper, the authors utilized the B-scan technique, with the probe placed in the superolateral of the globe, with the upper eyelid closed. The B-scan technique is very sensitive in detecting small optic nerve calcifications, such as in cases of optic nerve drusen,Other problems are related to the performance of the examination through closed eyelids, which makes impossible the recognition of gaze position and leads to Bell's phenomenon, with an upward and outward movement of the eye when an attempt to close the eyes is made. The consequence is the acquisition of images of optic nerve in different positions and measurements of sheath diameter stretched differently, thus not comparable.Moreover, with the eyelids closed, there is a decrease of the image quality score due to the sound attenuation produced by the lids, making the results even more unpredictable.For this reason, we suggest performing ocular ultrasonography with open eyelids, using methylcellulose and anesthetic drops.However, the best way to perform the examination is with a standardized A scan. It permits the unequivocal measurement of the ONSD with its hyperreflective spikes from the interface between the arachnoid and subarachnoid fluids, thus making the blooming effect harmless.There are a few other points that, in our opinion, deserve to be discussed.The case group is meaningfully heterogeneous: in fact, some of the patients (57.4%) were treated with acetazolamide, while the remaining (42.6%) were not.The authors found a negative correlation between ONSD and age, and a positive correlation between ONSD and body mass index (BMI).Unfortunately, both case and control groups are significantly different in age and BMI, making the comparison ineffective.We are afraid that all these problems could make the results of this study non significative.


Continuous cropping obstacles have become a serious factor restricting sustainable development in modern agriculture, while companion planting is one of the most common and effective methods for solving this problem. Here, we monitored the effects of companion planting on soil fertility and the microbial community distribution pattern in pepper monoculture and companion plantings. Soil microbial communities were analyzed using high-throughput sequencing technology. Companion plants included garlic (T1), oat (T2), cabbage (T3), celery (T4), and white clover (T5). The results showed that compared with the monoculture system, companion planting significantly increased the activities of soil urease (except for T5) and sucrase, but decreased catalase activity. In addition, T2 significantly improved microbial diversity (Shannon index) while T1 resulted in a decrease of bacterial OTUs and an increase of fungal OTUs. Companion planting also significantly changed soil microbial community structures and compositions. Correlation analysis showed that soil enzyme activities were closely correlated with bacterial and fungal community structures. Moreover, the companion system weakened the complexity of microbial networks. These findings indicated that companion plants can provide nutrition to microbes and weaken the competition among them, which offers a theoretical basis and data for further research into methods for reducing continuous cropping obstacles in agriculture. Capsicum of the Solanaceae family, is a widely cultivated vegetable in Ningxia, China. At present, improving the yield and quality of pepper has become a topic of interest as it is rich in capsaicin, ascorbic acid, vitamin C, and other nutrients, and exerts antibacterial and antioxidant functions [Pepper, a plant in the genus unctions . In receunctions , 3. ThesAs an effective way to solve continuous cropping obstacles, companion planting is not only one of the most common planting methods in modern agriculture, but also an important biological control measure . Compani5A large number of studies have shown that using the principle of allelopathy between plants and reasonably arranging companion plants or intercropping not only improves the yield and quality of vegetables, but also effectively reduces diseases and pests and improves the soil ecological environment to reduce the occurrence of continuous cropping obstacles , 11. Cowet al. found that alfalfa/mulberry intercropping not only enriched the diversity of bacteria [Proteobacteria, Actinomycetes and Firmicutes in mulberry intercropping, and Proteobacteria, Bacteroidetes, and Blastomonas in alfalfa intercropping were significantly higher than those in monoculture. Improving plant diversity directly increases the content and diversity of soil available carbon sources for microorganisms, which in turn increases their number, diversity, and activity, thereby inhibiting the invasion and reproduction of pathogenic bacteria [et al. reported that mustard and sesame as green manure can improve the disease resistance of cucumber Fusarium wilt by changing bacterial community composition in cucumber rhizosphere soil [Fusarium oxysporum and other fungi decreased after watermelon/upland rice intercropping, which significantly inhibited watermelon wilt disease [et al. also found that cucumber/onion intercropping significantly improved soil bacterial diversity in cucumber rhizosphere soil [Soil microorganisms, as the crucial source of soil enzymes, are involved in soil biochemical reactions and cause beneficial changes in soil enzyme activities. Meanwhile, intercropping utilizes the relationship between biodiversity and ecosystem function; for example, the increase in biodiversity is related to the increase in plant primary productivity . Cucumbebacteria , but alsbacteria , 20. Jinere soil . Their r disease . Zhou etere soil . Additioere soil . Furtherere soil . Contactere soil , 27, forere soil . TherefoGiven the above, it is also imperative to determine whether soil rhizosphere microbes of companion plants are different from those of individually cultivated plants. Therefore, this study employed high-throughput amplicon sequencing technology to characterize and compare various soil representative enzymes and microbial compositions, as well as their symbiotic network in pepper monoculture and several companion planting systems.Pepper  was the main crop in this study, and companion crops included garlic, oat, cabbage, celery and white clover, which can be used to control pepper continuous cropping diseases, according to previous research. The fertilizers used were special organic fertilizers for fruits and vegetables . The test soil was collected from a field under continuous cropping for 9 years in Xinji Township, Pengyang County, Ningxia Province, China. The soil properties were as follows: pH 8.53, total salt 3.22 g/kg, total nitrogen 0.12 g/kg, total P 0.89 g/kg, total K 39 g/kg, alkali-hydrolysed N 48 mg/kg, available P 40.66 mg/kg, available K 291 mg/kg, and organic matter 12.44 g/kg.i.e., 6 plots) were set for each treatment, which were randomly arranged and placed in the greenhouse for routine management. No chemical fertilizer was used during the trial period, but regular quantitative watering and manual weeding were carried out. After 50 days of companion treatment, the pepper rhizosphere soil was collected by the peeling separation method, and soil samples under the same treatment were mixed and divided into two parts, which were placed at 4°C and -80°C for enzyme activity determination and soil DNA extraction, respectively.The experiment was carried out at the Gongpeng Pepper Core Test Base in April, 2020, Xinji Township, Pengyang County, China. The test soil was mixed with organic fertilizer (v/10:1) and evenly loaded into 50 cm × 29 cm basins. Six treatments were set up: pepper monoculture , companion garlic (T1), companion oat (T2), companion cabbage (T3), companion celery (T4), and companion clover (T5). After sprouting, pepper was sown in seed trays and planted in pots at the 4-leaf stage, and each pot had 1 plant. Five days after colonization, the seeds of companion plants were planted in a semicircle approximately 5 cm away from the pepper plant and according to the sowing amount, seed germination rate, and emergence time studied by predecessors. Six replicates  [Urease was determined by indophenol blue colorimetry, with urea as the substrate. After culture, the urease enzyme product ammonia (ignoring the ammonia nitrogen loss caused by nitrification) reacts with phenol and sodium hypochlorite in alkaline medium to produce blue indophenol. Catalase belongs to the haemoglobin enzyme family and contains iron, and it can also catalyze the decomposition of hydrogen peroxide into water and molecular oxygen; therefore, the enzyme activity can be determined according to the consumption of Hic acid) .2), 5¢-GATGAAGAACGYAGYRAA-3¢ and P2 (ITS4), 5¢-TCCTCCGCTTATTGATATGC-3¢. After amplicon purification and quantification, an Illumina NovaSeq 6000 platform was used for paired-end sequencing (PE250). The raw reads were deposited in the NCBI Sequence Read Archive (SRA) database (Accession Number: PRJCA010600).Soil DNA extraction was performed by using the HiPure Soil DNA Kit  according to the manufacturer’s instructions. After genomic DNA extraction, the bacterial 16S rRNA gene V3-V4 region was amplified using the primer pair P1 (341 F), 5¢-CCTACGGGNGGCWGCAG-3¢ and P2 (806R), 5¢-GGACTACHV GGGTATCTAAT-3¢, while the fungal ITS2 gene region was amplified using the primer pair P1 (ITS3_KYOhttp://rdp.cme.msu.edu/) was used to analyze the taxonomy of each bacterial and fungal gene sequence against the Silva database (version 132) and Unite database (version 8.0) with a confidence threshold of 80% [http://circos.ca/). The linear discriminant analysis effect size (LEfSe) method was used to identify the most differentially abundant biomarker taxa among groups [p < 0.05) were retained for the visualization of networks using Gephi software [Analysis of the raw data was conducted using FASTP (V 0.18.0), including read filtering and splicing,  and FLASd of 80% , 34. A cg groups . Alpha-dg groups . To charsoftware -38. Genep-value of < 0.05 was considered statistically significant.One-way analysis of variance (ANOVA) with Duncan’s test was selected to analyze the differences in soil enzyme activities and α-diversity indices among all treatments. Analysis of similarity (ANOSIM) was performed to test whether the differences between groups were significantly greater than that within groups. Redundancy analysis (RDA) was performed to present the correlations between soil enzymes and microbial community structures using the vegan package in R with 999 permutations. Spearman correlation analysis was performed using IBM SPSS Statistics (v 25.0) . A p < 0.05), while soil catalase activity was significantly reduced (p < 0.05), and no significant differences were observed in the CK and T3 treatments.The soil enzyme activities of pepper in monoculture and five companion systems are shown in A total of 3,435,240 16S rRNA and 3,690,816 ITS quality sequences were obtained from all monoculture and companion soil samples, and the sequences were grouped into 4,825 bacterial and 542 fungal OTUs. The rarefaction curves  for all p < 0.05). For fungi, the T1 and T3 treatments significantly increased the number of OTUs, and T2 treatment resulted in an increase in the Shannon index compared to CK (p > 0.05), while fungal observed OTUs  and Shannon indices  had significant positive correlations with urease and sucrase activities   .Proteobacteria, Acidobacteria, Planctomycetes, Gemmatimonadetes, Actinobacteria, Bacteroidetes, Chloroflexi, Verrucomicrobia, Patescibacteria, and Firmicutes . The taxonomical classification showed that 137 bacterial genera were detected at the genus level. Sphingomonas, RB41, Lysobacter, Dongia, MND1, Acidibacter, Pseudoxanthomonas, Arenimonas, Altererythrobacter, and Ellin6055 were found to be the top 10 dominant bacterial genera . Only the relative abundance of RB41 had no significant difference in all treatments. In addition, 45 bacterial biomarkers were identified at the phylum, class, order, family, genus and species levels (LDA(log10) score > 3.5)  .Kotlabaea, Cladorrhinum, Coprinellus, Madurella, Schizothecium, Tetracladium, Pseudogymnoascus, Podospora, Scedosporium, and Mortierella were the top 10 dominant fungal genera  score > 3.5)  .p < 0.05). Compared to CK, the numbers of nodes and edges in the five companion planting networks decreased, indicating that companion planting reduced the relationships among microorganisms, thus weakening the symbiotic patterns of the microbial community. In addition, the average degrees and clustering coefficients in the T3 and T5 treatments were lower than those of the control (CK), while the opposite results were observed in the T4 network. The network diameter in all companion treatments decreased compared to CK. Moreover, significant differences were also observed in the topological structure characteristics of the symbiosis network between control and companion planting treatments. Overall, companion planting treatments affected the network complexity of the microbial community. Additionally, there were differences in the keystone taxa in the microbial networks between the control and five companion planting treatments (Microbial co-occurrence network analysis was conducted to explore the co-occurrence patterns among bacteria and fungi at the genus level in soil. As shown in eatments . There wSoil biological activity, referring to the transformation, release, and fixation of soil nutrients, is an important indicator to assess soil fertility and health status . HoweverSoil enzymes are involved in soil biochemical processes and play key roles in the occurrence, transformation, and availability of soil nutrients. They can reflect soil biological activity and biochemical reaction intensity, and are also sensitive to external environmental changes. Moreover, soil enzyme activities are important biological indicators of soil fertility, quality and health ; for exaSoil microbial diversity plays an important role in maintaining multiple functions in terrestrial ecosystems , and theProteobacteria, Acidobacteria, Planctomycetes, Gemmatimonadetes, Actinobacteria, Bacteroidetes, Chloroflexi, Verrucomicrobia, Patescibacteria, and Firmicutes (Proteobacteria was the dominant phylum in most studies [Proteobacteria and Chloroflexi, which was inconsistent with the results of previous intercropping studies [Proteobacteria feed on different stubborn carbon sources and strongly impact soil microbial community structures by providing functional capacity for the carbon cycle and more available nutrients for plant growth [Fusarium was not the dominant fungus in this study, indicating that companion planting improves soil resistance and reduces its pathogenicity [Intercropping has been shown to change soil microbial community compositions . Changesrmicutes , suggest studies , 58, whi studies . In this studies . The reat growth , 60. As t growth , 62. Ourt growth . Ascomyct growth . Ascomyct growth . In addigenicity . These rgenicity . Meanwhigenicity .et al. [Network analysis can be used to determine the interactions of microbial taxa in a niche and the keystone species that have the greatest impact on the microbial community . A symbiet al.  found thIn this study, RDA plots showed that soil enzyme activities were significantly correlated with soil microbial community structures, including urease, catalase, and sucrase . In addiTo sum up, soil microbial community distribution patterns of pepper monoculture and companion plantings were compared using high-throughput sequencing technology. The results showed that companion planting significantly increased soil urease and sucrase activities, but decreased catalase activity compared to the monoculture system. In addition, companion planting improved the microbial diversity in pepper continuous cropping soil, and significantly changed soil microbial community structures and compositions. Soil enzyme activities were also found to be significantly correlated with microbial community structures. Moreover, the companion system reduced the complexity of microbial community networks, which may result in the provision of microbial nutrition and weaken the competition among microorganisms. These results should provide a theoretical basis and data for further research on reducing continuous cropping obstacles in agriculture.http://jmb.or.kr.Supplementary data for this paper are available on-line only at